如何解决Android Studio中的in fragment问题

将case R.id.home;改为case R.id.home:(分号改为冒号).R.id.settings也一样.例如:

public boolean onNavigationItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.home:
            getSupportFragmentManager().beginTransaction().replace(R.id.container, homeFragment).commit();
            return true;
        case R.id.settings:
            getSupportFragmentManager().beginTransaction().replace(R.id.container, settingsFragment).commit();
            return true;
    }
    return false;
}

请注意，您可能还会在"Switch Case语句进一步研究here"中得到关于"非最终资源ID"的warning.

消除预期警告的一种解决方案如下:

public boolean onNavigationItemSelected(MenuItem item) {
    if (item.getItemId() == R.id.home) {
            getSupportFragmentManager().beginTransaction().replace(R.id.container, homeFragment).commit();
            return true;
    }
    if (item.getItemId() == R.id.settings) {
            getSupportFragmentManager().beginTransaction().replace(R.id.container, settingsFragment).commit();
            return true;
    }
    return false;
}

顺便说一句，视频中确实有它作为冒号.